Sacred Fire is a Physical Fire-type move with 100 base power, 95% accuracy and a 50% chance to inflict the Burn status on the target. It was originally Ho-Oh's signature move, meaning it was the only one that could learn it naturally before Generation VI, when it was also added to Entei's movepool.

Ho-Oh is treated as a "legendary" Poké Ball Pokémon; its chance of appearing is much rarer than most of the others, and in return, its effect is more powerful. Ho-Oh uses its signature move from the RPGs, Sacred Fire. Ho-Oh will fly up into the air and to the back of the screen when it's summoned. Once Ho-Oh starts flying upwards, any character other than the summoner that makes contact with it will take 13% damage and decent knockback. Ho-Oh will then release a column of fire. Characters other than the summoner that are caught in the column of fire take massive damage (up to 125%), and it is quite difficult to escape from it.

The attack occurs a full seven seconds after Ho-Oh's release, making it the longest delay for a Pokémon attack. Ho-Oh covers a very large attack area, although the heavy delay and predictability of the attack's location (it always appears where Ho-Oh was released) make it relatively easy to avoid, although the summoner can try to make sure that his or her opponents will be in that particular spot when the attack actually occurs.

Ho-Oh appears as a collectible trophy, unlocked as one of the trophies that can be collected randomly in the Trophy Lottery, though it only appears once all characters have been unlocked. It uses the capitalization "Ho-oh", as the "Ho-Oh" capitalization didn't appear until Generation III.

The Ho-Oh trophy from Melee.

Ho-oh

As it soars around the skies of the world, this Rainbow Pokémon leaves a trail of rainbows and myths in its wake. Its signature move is called Sacred Fire, and it is believed to appear only before trainers who are pure of heart. If you see a trainer with Ho-oh, you can assume that catching it took a lot of work. (Pokémon Gold & Silver 10/10)

Ho-Oh returns in Brawl, receiving a buff with respect to its Melee version. It once again uses Sacred Fire, but the pillar of fire is larger and can interfere with vision. A character who touches the pillar of fire will be sucked down into its the center: this means that if Ho-Oh is released from its Poké Ball at the very edge of a stage anyone who touches the fire pillar will be sucked down and subsequently meteor smashed. It also performs knockback at the end of the move.

A Rainbow Pokémon. On sparkling wings of seven colors, Ho-Oh leaves a rainbow behind as it flies. Legend says that Ho-Oh suppressed a war that scorched the land in ancient times. Its attack Sacred Fire can melt ice in an instant and also damage the target with burns. Ho-Oh will show its solemn figure only for the most righteous Trainers.

Ho-Oh no longer appears as a Poké Ball Pokémon and instead appears as a stage element in the Kalos Pokémon League stage, as the legendary Pokémon that rarely appears in the Blazing Chamber. It makes the flames supporting the platforms flare up with higher intensity.

This Pokémon flies through the skies, trailing rainbows from its wings, and is said to promise eternal happiness to all who see it. Supposedly, it appears every once in a while in the Fire-type Elite Four Trainer's room in the Kalos Pokémon League stage. Its screams cause pillars of fire to rise all the way to the ceiling.